Automatic Welding Equipment Heavy Oil Catalytic Cracking Unit

A variety of automatic welding equipment is often involved in the welding production process of pressure vessels, such as: electroslag welding machine, submerged arc welding machine, gas shielded welding machine (CO2 welding machine and argon arc welding machine, etc.), plasma welding machine, etc. my country's pressure vessel welding automation technology started in the 1950s and 1960s, and has made great achievements so far. In recent years, domestic automatic and semi-automatic welding machines have accounted for 20.55% of the total number of welding machines, MIG/MAG welding machines have increased by 63.12%, TIG welding machines have increased by 19.24%, and submerged arc welding machines have increased by 135.36%. As a new technology and new process, the inverter welding machine has excellent welding performance and electrical performance, and is suitable for various arc welding methods and multi-position welding of pressure vessels. The application degree of inverter welding in the United States and Japan has reached 30%, and the inverter welding machine in my country has developed into the third generation product, and the application prospect in the domestic pressure vessel industry is very optimistic. Such as: Dongfang Boiler Factory, Haiqing Heavy Industry Machinery Co., Ltd., Lanzhou Petrochemical Machinery Factory, etc. have used TIG and CO2 inverter welding machines for all-position welding of boilers and pressure vessels. In the early 1990s, multi-head submerged arc automatic welding and multi-head MAG automatic special welding machines have been developed in China. At present, more than ten units in China have used domestic-made water-cooled wall special welding machines. As a typical program-controlled flexible welding system, modern welding robots, especially arc welding robots, have the advantages of high efficiency and stable quality, and are highly valued in the field of pressure vessel welding. Flexible welding robots will be popularized and applied in my country as their prices continue to decrease, becoming a development direction of microcomputer automation control technology for welding equipment. In addition, the improvement of some process equipment, such as: hydraulic head and cylinder assembly equipment, universal welding turntable, automatic longitudinal seam circumferential seam welding device for small diameter cylinders, etc., have also greatly improved the pressure vessel. The degree of welding automation.

Automated welding method

Submerged arc automatic welding is the main process method of pressure vessel welding at present. However, most of the domestic automatic submerged arc welding control systems still use simple analog circuits, and the overall performance needs to be further improved. The surfacing technology is mainly used for the welding of thick-walled pressure vessels. Among them, submerged arc surfacing welding has become the main method for surfacing the inner wall of pressure vessels at home and abroad due to the shallow and uniform base metal penetration and low requirements on the surface quality of the workpiece. The recently developed high-speed strip surfacing method, compared with strip submerged arc surfacing, has finer grain boundaries and low impurity content in the surfacing layer, which is a more economical surfacing method. Narrow gap welding technology can perform all-position welding for thick-walled pressure vessels, which is easy to automate the welding process. At present, this technology realizes the preset parameters before welding, automatically stabilizes the welding voltage, current and speed, and has an automatic height and lateral tracking system to realize the automatic welding of the welding seam. Gas shielded welding has the advantages of concentrated arc heat, small molten pool, fast crystallization and no slag in the welding process. It is mainly used for all-position and thin plate welding, which is conducive to the mechanization and automation of the welding process. CO2 welding is a high-efficiency welding method. my country Petroleum and Natural Gas No. 7 Construction Company introduced the spherical tank flux-cored wire all-position automatic welding technology from the United States. The welding deposition efficiency is high, the speed is fast, and the welding conditions are improved. TIG welding technology is mainly used for pressure vessels with high requirements on weld sealing performance and mechanical properties. It can precisely control the penetration volume and shape, and can better realize all-position welding of pressure vessels. Due to its extremely high energy density and extremely small HAZ area, laser automatic welding technology can weld almost all metals and can perform all-position welding. It has been developed for the welding of thick-walled pressure vessels, but due to its high price and cumbersome equipment, The prospect of application in pressure vessels remains to be seen.

Welding Control Technology

In recent years, welding automatic control technology has been greatly developed in the pressure vessel industry. Weld seam tracking is an important part of the welding automation control system, which has far-reaching significance for the realization of welding automation in the production process of pressure vessels. At present, the applied welding seam tracking system mainly includes two types: contact type and non-contact type. The contact mode tracking system keeps the distance between the contact tip and the welding seam constant through the horizontal tracking, vertical tracking and fine-tuning system, and realizes the automation of circular seam welding. measurement accuracy. The contactless tracking system is closely related to other disciplines, and scholars at home and abroad have carried out researches on it to varying degrees. The non-contact ultrasonic tracking sensor is used on the submerged arc welding machine to perform the welding seam tracking of the welding seam groove detection, which can meet the needs of pressure vessel manufacturing and has a good application prospect in low-cost welding automation. The CCD-based visual seam tracking system can be used in various welding methods and equipment such as submerged arc welding and plasma arc welding. However, in view of the harsh application environment of the welding process, the sensor is subject to the interference of arc light, high temperature, smoke, etc. Accuracy, anti-jamming performance and sensitivity are affected to varying degrees. Although a variety of automated tracking methods have been developed to date, most are still in the experimental stage. With the development of computer information technology and the research of new sensing methods, the welding seam tracking technology will be widely used in the pressure vessel industry to further improve the automation and intelligence of the pressure vessel welding process.

Artificial Intelligence Technology and Expert System

The representative artificial intelligence technology in welding process is fuzzy control system, neural network control system and welding expert system. I11-Soo Kim et al. introduced the artificial neural network into the GMA welding method to predict the width of the welding zone, which broadened the application field of GMA welding. At present, the United States, Japan and other countries have successively carried out a series of research and development in process formulation, defect analysis, material selection and equipment selection. Camtech 100 and Adaptitech 1000 developed by Adaptive Technologies in the United States can complete functions such as part positioning, welding operation and quality inspection. The system can automatically adjust the welding path, line energy, wire feeding speed and Swing parameters, etc., and can optimize multi-pass welding parameters. The "Welding Parameter Control Expert System" developed by Japan's NKK Company can provide optimal welding parameters to ensure constant penetration and welding height. my country has also developed different types of application software in this field. Among them, the "General-purpose arc welding process expert system QHWES" developed by Tsinghua University is unique because of its strong adaptability and redevelopment ability. At present, a variety of commercial products have been formed at home and abroad, and they have broad development and application prospects.